Superparamagnetic iron oxide nanoparticle layer with high packing density and controlled thickness were in situ deposited on metal-affinity organic templates (polydopamine spheres), via one-pot thermal decomposition. The as synthesized hybrid structure served as a facile nano-scaffold toward hollow-mesoporous magnetic carriers, through surfactant-assisted silica encapsulation and subsequent calcination. Confined but accessible gold nanoparticles were successfully incorporated into these carriers to form recyclable catalyst, possessing quick magnetic response and large surface area (642.5 m2 g-1). Current nano-reactors exhibited excellent catalytic performance and high stability in reduction of 4-nitrophenol, together with convenient magnetic separability and good reusability. The integration of compact iron oxide nanoparticle layer with programmable polydopamine templates paves the way to fabricate magnetic-response hollow structures, with high permeability and multi-functionality.